@Guy Stewart (Victron Energy Staff) I recently installed 3 x Multigrid 48V 3000's in parallel on a single phase installation feeding 2 x sub-mains on the AC output to a separate house and shed each with a sub-board and MEN link. The system is coming up with Error 11 due to these N-E connections and the only solution offered by Victron so far is to replace the 3 x Multigrids with 3 x Multipluses and then install special firmware to disable the N-E checks on initial start-up. I have asked if firmware can be provided to solve the problem with the existing Multigrids with the answer being "no, the Multigrid's cannot be modified". It is not practical to install separate earths to these sub-boards due to difficulty and length, is there another known solution before removing and replacing the Multigrids with Multipluses?